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Cranial Morphology of Domestic and Wild Canids: The Influence of Development on Morphological Change Robert K. Wayne Evolution, Vol. 40, No. 2 (Mar., 1986), pp. 243-261

D. Phillip Sponenberg. Inheritance of the harlequin color in Great Dane dogs J Hered (1985) 76 (3): 224-225

Ruvinsky, Anatoly, and J. Sampson. The Genetics of the Dog. Wallingford, Oxon, UK: CABI Pub., 2001. Print.

S. M. Schmutz, T. G. Berryere, N. M. Ellinwood, J. A. Kerns,and G. S. Barsh MC1R Studies in Dogs With Melanistic Mask or Brindle Patterns. J Herald (2003) 94 (1): 69-73.

The Early Evolution of the Domestic Dog. Darcy F. Morey American Scientist, Vol. 82, No. 4 (JULY-AUGUST 1994), pp. 336-347

https://en.wikipedia.org/wiki/Great_Dane

It would be great to have information about how Great Danes started to become apart of people's families and brought inside to be house dogs opposed to just hunting dogs. Also, having more information about how the different colors came about would be helpful. Fuerst.36 Fuerst.36 (talk) 03:02, 2 October 2014 (UTC)

Although two Harlequins may breed together, they will always reproduce at least one merle.

Paper (revised): Throughout centuries of Earth’s history, canines have been around. Many years ago, dogs became more than just another animal roaming the Earth. Dogs did not become “man’s best friend” all of a sudden. It was a relationship that developed over many years and is still continuing to develop today. Starting with wild dogs and wolves, humans have transformed them into a wide variety of breeds. Numerous breeds have a plethora of colors they can be bred for, while other breeds only come in one or two colors. Each breed was bred for specific reasons, whether it was to hunt a certain animal or help pull heavy objects. This is the reason why we still have different groups of dogs today, such as the working group or sporting group. Great Danes are among one of the many breeds in the working group and are a breed that can come in many different colors or a combination of colors. People often wonder how dogs began to have so many different colors when their ancestors, the wolves, only started with just one or two colors. Through years and years of careful breeding and genetics, Great Danes have evolved to have the varying colors in their coats and have developed into a well-known breed.

Dogs becoming a part of people’s lives did take time. As many as twelve thousand years ago, wolves were starting to make an appearance with humans more often. Dogs are the only animals that have had such a close and long relationship with humans (Ruvinsky et al., 2001). Domesticating dogs happened at different rates all over the world. During similar time periods in certain areas, it is clear that dogs were still being used as a source of food, while in other area dogs were being used to pull sleds and aide in human’s everyday needs (Morey et al., 1994). Today, researchers believe the Grey wolf is the ancestor that is most closely related to the domesticated dog since their genes are almost identical aside from a few differences.

As wolves became domesticated, changes not only happened in their behavior, but physical changes also occurred. Studies show that the actual size of a domestic dog’s brain and a wild dog’s brain vary. The closest relative domestic dogs have when comparing brain size is their ancestor the wolf. Researchers have also found brain size an important component to tracing breeds in domestic dogs (Wayne et al., 1986). Scientists still argue whether the domestication of wolves and wild dogs was intentional or if this process was caused by evolution through natural selection. (Morey et al., 1994) Some scientists still believe in the idea that natural selection actually caused wild dogs to become domestic because they have a hard time believing humans were the only factor that led to domestication of dogs.

The Great Dane is one breed that has been around for a long time. People normally are able to identify the Great Dane because of its large size. Their size is actually the original reason why they were bred and what they were used for. Dating all the way back to the 16th century, Great Danes were used for hunting. Since Great Danes are large, people had them hunt large game. Great Danes were used for hunting bears and boars. Once guns started to be used as the main weapon for hunting, hunters no longer needed Great Danes for their hunting capabilities. Although they began to be used for hunting in the sixteenth century, Great Danes are seen as early as 3,000 BC on Egyptian monuments (Great Danes, 2014). Unfortunately due to Great Danes large size, they do not have a long life span. A typical life-span for a Great Dane is no more than eight years.

Many people have no idea that Great Danes can come in so many different colors and variations of those colors. Great Danes can come in seven different coat colors: fawn, blue, brindle, mantle, black, grey merle and harlequin. There are also colors that are not accepted through showing, which includes white and mixes between two of the other acceptable colors. These colors started to form as early as when dogs first started becoming domesticated. Colors that people assumed would be natural in domesticated dogs may actually not be, such as the color black. Black coat color was actually caused by a mutation. Many mammals are able to pass on a gene that causes black coat color, however, dogs do not pass that gene on in a dominant manner like other mammals do (Candille et al., 2007).

Like in many other breeds there are certain coat colors that are more popular than others. In Great Danes, the harlequin color, which is a white coat with black and sometimes gray patches, is very popular and one of the most sought after coat colors. Once again this particular color is caused by a mutation (Sponenberg et al., 2006). When breeding for the harlequin color, Great Danes will always produce dogs with the merle coat color. With mutations as a huge decider upon coat colors, breeders must be careful what colors they breed together. With some dogs breeding together it could be fatal for some, if not all, offspring. Very few breeds of dog are actually able to produce the harlequin coat color, which makes it a less common coat color in dog breeds. Without mutations within coat color genes, we would not have as wide of a variety of different coat colors as we do today.

A coat color that is more common amongst dog breeds is brindle. This color is also caused by a mutation within the MC1R gene. Typically the MC1R gene causes a solid yellow or red color often seen in Labradors or Golden Retrievers. However, when the mutation occurs it causes a dog to have a black mask rather than the darker brown hue amongst the yellow or reddish coat color. New coat colors within a breed are possible with so many mutations occurring in each color (Schmutz et al., 2003).

Great Danes have been around for centuries and have evolved into a dog that is not only well known, but has an array of varying colors. It took people many years to domesticate the wild dog and make different breeds into exactly how they wanted them to be. It is amazing to see a dog like a Chihuahua and a Great Dane and know that they both have a common ancestor of a wolf. Although not all domesticated dogs have as many coat colors as the Great Dane that does not mean that people are not trying to create a new color. Even today with people breeding new dogs together, today’s society is starting to see breeds with a wider variety of coat colors or breeds with a new coat color that have never been seen before. There are many different reasons for the wide variety in coat color, but it is mostly due to mutations.

Edit added to page: Suggested to add information about mutations involved in creating certain coat colors, such as brindle being caused by a mutation within the MC1R gene.